66 EXPLANATION OF PLATES. 
bunches of spines, more or less developed ; 6-8, old bunches of spines; 9, fruit, with a few 
scales, with wool at base and the dry flower on top; 10, seed. 
Px. 35, fig. 1-5. Ecurvocactus INTeRTExTus, var. Dasyacantuus: 1, 1-2, young bunches of 
spines ; 3-5, old ones. 
Fig. 6-8. Ecntocactvs unavisrryus, bunches of spines. 
Pr. 36, Cereus vrriprerorus: 1, large plant from the Limpia in flower, one flower fully, 
another one half open; 2, bunch of spines of this plant without, and 3 with a central spine ; 
- 4-7, bunches of spines of a specimen collected by Dr. Bigelow on the upper Pecos, with 1 or 
more central spines; 4, a very young bunch; 5, a full grown one; 6, a similar larger one like 
the former, with 2 central spines; 7, another one, with the largest central spine curved 
upwards ; 8-10, bunches of spines with and without a central spine, from plants collected by 
Dr. Wislizenus in northeastern New Mexico; 11, part of a plant in flower, with very obtuse 
petals and very small spines, collected by A. Fendler at Santa Fé; 14, fruit from Santa Fé; 
15, seed of the same; 16, fruit from the Limpia. 
Pu. 37. CEREUS CHLORANTHUS in full bloom, 
Pi. 38. The same: 1, top view, exhibiting the rays formed by the central spines; 2-7, 
different bunches of spines; 8, a small fruit; 9, one of usual size; 10, seed of common size ; 
11, smaller seed. 
Pi. 39, CrREUs DASYACANTHUS, a simple, branchless plant, with one flower. 
Pu. 40. The same: bunches of spines, different in size, number, and proportion of the spines ; 
all twice magnified. 
Pu. 41, fig. 1-2. The same: 1, fruit; 2, seed. 
Fig. 3-5. Cernvs Rorrrert: 3-4, bunches of spines, magnified twice ; 5, a fruit. 
Pr. 42. Cereus crenomes: 1, a large specimen in flower; 2-3, front view and lateral view of 
a bundle of spines, twice magnified ; 4, top part of another specimen, in which the spines are 
not so closely pectinate ; 5-6, spines of this specimen, twice magnified. 
Pu. 43. Cereus casprtosus: a specimen of one of the largest forms; petals unusually curled. 
Ps, 44. The same: 1-4, spines of the larger form, in different states of development, magnified 
twice ; 5-7, spines of the smaller form, also magnified twice ; some of the bunches show rudi- 
ments of central spines; 8, a fruit with the rudiments of the flower shrivelled up; 9, a fruit 
exhibiting yet the tube of the flower very distinctly ; 10-11, seed of the larger, and 12, seed of 
the smaller form ; 11, g, young seedling soon after germination. 
Pt, 45, CEREUS LONGISETUS. 
Pu. 46. Cereus srramineus: One head out of a plant with numerous heads. 
Pu. 47, The same: Another head with smaller spines, seen from above ; 2-4 bunches of spines ; 
5, fruit; 6, seed of the same, usual size ; 7, seed of another specimen larger than usual, 
Pu. 48. Fig. 1. A flower of the same. 
Fig. 2-4. Cereus enneacantuus: 2, part of a stem showing the ribs and spines and a flower 
from El Paso ; 3, flower of a specimen from Eagle Pass; 4, bunch of spines from El Paso ; 
which, however, may belong to a form of ©. stramineus ; lower central spine triangular and 
much flattened. 
Pu. 49. The same: 1, head of a specimen from Eagle Pass; 2, another one with longer and 
stouter spines ; 3-10, bunches of spines of plants collected at Eagle Pass and at El Paso; 10, 
with a curved central spine; 11, fruit, belonging to flower, fig. 3, of last page; 12, seed of 
same, 
